[143]. See U.N. Charter art. 2(4) and related customary rule.
[144]. See Part III.D.
[145]. See Part III.B.
[146]. But see U.N. Charter art. 33(1) (“The parties to any dispute, the continuance of which is likely to endanger the maintenance of international peace and security, shall, first of all, seek a solution by negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, resort to regional agencies or arrangements, or other peaceful means of their own choice.”). See generally Claus Kreß, The International Court of Justice and the ‘Principle of Non-Use of Force’, in The Oxford Handbook of the Use of Force in International Law 561–604 (Marc Weller ed., 2015); Vaios Koutroulis, The Prohibition of the Use of Force in Arbitrations and Fact-Finding Reports, in The Oxford Handbook of the Use of Force in International Law 605–26 (Marc Weller ed., 2015); Mark Weisburd, Use of Force: Justiciability and Admissibility, in The Oxford Handbook of the Use of Force in International Law 329–46 (Marc Weller ed., 2015).
[147]. We do not address treaty provisions pertaining to the non-use of force that are laid down in regional or bilateral treaties.
[148]. For its part, the ICJ held in the Military and Paramilitary Activities in and against Nicaragua case that “[t]here can be no doubt” that at least certain “issues of the use of force and … self-defence … are issues which are regulated both by customary international law and by treaties, in particular the United Nations Charter.” Military and Paramilitary Activities in and against Nicaragua (Nicar. v. U.S.A.), Judgment, 1986 I.C.J. Reports, 16, 27 (June 27) (emphasis added) (hereinafter, Military and Paramilitary Activities, Judgment).
[149]. Id. (referring to the French text (“droit naturel”) and to English text (“inherent right”) in the first sentence of article 51 of the U.N. Charter) (emphasis added).
[150]. Id. at 96–97.
[151]. On simultaneous regulation by treaty law and customary international law, see Buga, above note 28, at 209; Rebecca Crootof, Change Without Consent: How Customary International Law Modifies Treaties, 41 Yale J. Int’l L. 237 (2016); Bing Bing Jia, The Relations between Treaties and Custom, 9 Chinese J. Int’l L. 81 (2010); Yoram Dinstein, The Interaction Between Customary International Law and Treaties, 32 Recueil des cours 246 (2007); Mark E. Villger, Customary International Law and Treaties: A Manual on the Theory and Practice of the Interrelation of Sources (2d ed., 1997).
[152]. See generally Tom Ruys, ‘Armed Attack’ and Article 51 of the UN Charter (2010).
[153]. See, e.g., Olivier Corten, Necessity, in The Oxford Handbook of the Use of Force in International Law 861–878 (Marc Weller ed., 2015).
[154]. See, e.g., Sina Etazazian, The nature of the self-defence proportionality requirement, 3 J. Use of Force & Int’l L. 1 (2016).
[155]. See generally Christine Gray, International Law and the Use of Force (4th ed., 2018); Yoram Dinstein, War, Aggression and Self-defence (6th ed., 2017); Olivier Corten, The Law Against War (2012).
[156]. But see Rome Statute of the International Criminal Court arts. 8 bis, 15 bis–15 ter, 2187 U.N.T.S. 3 (entry into force July 1, 2002) (jurisdiction over the crime of aggression).
[157]. On the question concerning modification of jus cogens norms, see Dinstein, above note 151, at 397–403.
[158]. See Buga, above note 28, at 107–194.
[159]. See id. at 195–235.
[160]. Jessica Liang, Modifying the UN Charter through Subsequent Practice: Prospects for the Charter’s Revitalisation, 81 Nordic J. Int’l L. 1, 19 (2012) (“Larger changes, especially when consistently attempted, are bound to attract controversy and produce objections. In this regard, the most immediate field of operation under the Charter is that of the use of force. Given the strong textual presumption against the use of force as construed from Article 2(4) and the limited circumstances in which the use of force is permitted under Article 51 and Chapter VII, it will be extremely hard to modify the existing practice as derived from the text.”) (citing to Andrea Bianchi, The International Regulation of the Use of Force: The Interpretive Method, 22 Leiden J. Int’l L. 651, 665 (2009)).
[161]. See Olufemi Elias, The Nature of the Subjective Element in Customary International Law, 44 Int’l & Comp. L. Quart. 501, 509 (1995) (arguing that “[s]ome States initiate a practice, but we do not look to them for opinio juris; rather, we look to the reactions of other States to the new position. If these other States consent to (i.e. agree, acquiesce in, comply with, concur with or permit) this new practice, then there is opinio juris in relation to this new practice.”) (citation omitted). See also Buga, above note 28.
[162]. Dinstein, above note 151, at 322 (emphasis added).
[163]. Id. at 323.
[164]. Id.
[165]. Rosalyn Higgins, International Law and the Avoidance, Containment and Resolution of Disputes: General Course on Public International Law, 230 Recueil des cours 9, 44 (1991). See further id. (arguing that “this characteristic is more troublesome for those who regard law as rules, and less troublesome for those who regard law as process. But whether one believes that international law consists of rules that have been derived from consent or natural law, or whether one believes international law is a process of decision-making, with appropriate reliance on past trends of decision-making in the light of current context and desired outcomes, there still remains the question of how the ‘rules’ or the ‘trend of decision’ changes through time. And in so far as these rules or trends of decision are based on custom, then there is the related question of what legal significance is to be given to practice that is inconsistent with the perceived rules or trend of decision.”).
Whether the practice and/or opinions of so-called “specially affected” States may play a (particular) role in relation to the development of customary international law on recourse to force is a subject of debate in international scholarly discourse. See, e.g., Ruys, above note 152, at 38 (inferring from ICJ jurisprudence “that acquiescence matters most when it emanates from States directly concerned with a concrete recourse to force (for instance the State against which self-defence is exercised or neighbouring States) or from a large number of States.”) (citing to Buzzini, above note 6, at 85–6, 104). On “specially affected” States, see Kevin Jon Heller, Specially-Affected States and the Formation of Custom, 112 Am. J. Int’l L. 191 (2018). Also, with respect to a so-called “persistent objector,” per the ILC, “[w]here a State has objected to a rule of customary international law while that rule was in the process of formation, the rule is not opposable to the State concerned for so long as it maintains its objection.” Draft CIL Conclusions, above note 88, at 121 (draft conclusion 15, para. 1). The ILC indicates that that formulation is without prejudice to any question concerning peremptory norms of general international law (jus cogens). Id. (draft conclusion 15, para. 3).
[166]. Marques Antunes, above note 6, at para. 16 (arguing that “acquiescence is dispensed with, as far as their [that is, jus cogens norms’] binding nature is concerned”).
[167]. Id. at para. 14. With respect to obligations erga omnes, see Bianchi, above note 160, at 663 (“Indeed, silence towards significant events, potentially affecting the interests of all states, remains enigmatic, all the more so when one realizes that nowadays many are the international fora in which states can express themselves. The relevance of acquiescence and the wider significance of the lack of reaction even by those states that are directly affected by such uses of force ought to be carefully analysed in any serious attempt to discern states’ opinio juris.”) (citations omitted).
[168]. Id. For a skeptical view on whether acquiescence in the face of a violation of a peremptory jus ad bellum norm may lead to the establishment of a new or extended right to resort, see Nigel D. White, The Will and Authority of the Security Council after Iraq, 17 Leiden J. Int’l L. 645, 663 (2004) (“Furthermore, one should not quickly assume acceptance in the face of rules that are peremptory, such as that prohibiting the threat or use of force in Article 2(4). When practice is apparently violative of a peremptory norm, it is not enough to have acquiescence in the face of the violation in order to establish a new or extended right. It is argued that there needs to be more positive acceptance of the claim, positive proof that states have accepted the modification of the peremptory norm, proof in other words of opinio juris. Arguments about acquiescence seem to assume the emergence of new rights in a legal vacuum, but that is not the case. Brownlie puts this clearly when he states that ‘the major distinguishing feature of such [peremptory] rules is their relative indelibility. They are rules of customary law which cannot be set aside by treaty or acquiescence but only by the formation of a subsequent customary rule to contrary effect’.”) (emphasis added; quoting Brownlie, above note 36, at 488).
[169]. See (Draft) Articles on State Responsibility art. 41(1), above note 138, at 29; (Draft) I.O. Responsibility Articles art. 42(1), above note 138, at 62. With respect to States, see generally Paolo Palchetti, Consequences for Third States as a Result of an Unlawful Use of Force, in The Oxford Handbook of the Use of Force in International Law 1224–38 (Marc Weller ed., 2015).
[170]. See (Draft) Articles on State Responsibility art. 41(2), above note 138, at 29; (Draft) I.O. Responsibility Articles art. 42(2), above note 138, at 62.
[171]. John Quigley, The Afghanistan War and Self-Defense, 37 Valparaiso Univ. L. Rev. 541, 554 (2003).
[172]. It has been argued in respect of a different context — namely, whether the Council is bound to respect international law, including human rights, and thus has an obligation, under certain conditions, to act positively and not abstain — that “under the lex lata, passivity of the Council has not given rise to its international legal responsibility.” Anne Peters, Article 24, in I The Charter of the United Nations: A Commentary 850, marginal note 199 (Bruno Simma, Daniel-Erasmus Khan, Georg Nolte, & Andreas Paulus eds., Nikolai Wessendorf assistant ed., 3d ed., 2012).
[173]. Quigley, above note 171, at 554.
[174]. Id.
[175]. Alexander Orakhelashvili, Changing Jus Cogens Through State Practice? The Case of the Prohibition of the Use of Force and its Exceptions, in The Oxford Handbook of the Use of Force in International Law 171 (Marc Weller ed., 2015).
[176]. Legal Consequences of the Continuing Presence of South Africa in Namibia, 1971 I.C.J. Reports, 16, 36 (June 21) (emphasis added) (hereinafter, Namibia, Advisory Opinion). See Alexander Orakhelashvili, above note 175, at 174.
[177]. See U.N. Charter arts. 24–26.
[178]. See id. at art. 39 (“The Security Council shall determine the existence of any threat to the peace, breach of the peace, or act of aggression and shall make recommendations, or decide what measures shall be taken in accordance with Articles 41 and 42, to maintain or restore international peace and security.”) (emphasis added).
[179]. See id. at art. 42 (“Should the Security Council consider that measures provided for in Article 41 [that is, measures not involving the use of armed force] would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action may include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations.”) (emphasis added). In the Nuclear Weapons advisory opinion, the ICJ stated that “[a] further lawful use of force” — that is, beyond the recognition in article 51 of the inherent right of individual or collective self-defence if an armed attack occurs — “is envisaged in Article 42, whereby the Security Council may take military enforcement measures in conformity with Chapter VII of the Charter.” Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996, 226, 244 (July 8) (hereinafter, Nuclear Weapons, Advisory Opinion).
[180]. See id. at art. 51 (“Nothing in the present Charter shall impair the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security.”) (emphasis added).
[181]. Draft Subsequent Agreement Conclusions, above note 65, at 15 (draft conclusion 12, para. 3) (emphasis added).
[182]. Stefan Kadelbach, Interpretation of the Charter, in I The Charter of the United Nations: A Commentary 80, marginal note 18 (Bruno Simma, Daniel-Erasmus Khan, Georg Nolte, & Andreas Paulus eds., Nikolai Wessendorf assistant ed., 3d ed., 2012) (emphasis added; citing to Namibia, Advisory Opinion, above note 176, at 22).
[183]. The United Nations and International Law, in I Oppenheim’s International Law: United Nations 415, marginal note 12.04 (Rosalyn Higgins, Philippa Webb, Dapo Akande, Sandesh Sivakumaran, & James Sloan eds., 2017) (citations omitted).
[184]. Compare Jan Klabbers, Intervention, Armed Intervention, Armed Attack, Threat to Peace, Act of Aggression, and Threat or Use of Force: What’s the Difference?, in The Oxford Handbook of the Use of Force in International Law 500 (Marc Weller ed., 2015) (“the Council is a political organ, endowed with a political task, and while its decisions will inevitably be accompanied by legal fall-out, it is not for the Council to assume the role of judicial body or lawmaker.”) and Kadelbach, above note 182, at 93, marginal note 56, with Military and Paramilitary Activities, Judgment, above note 148, at 105 (expressing the view, in obiter, that, at least as a matter of the treaty law of the Charter, the Security Council is “empowered to determine the conformity with international law of the measures” reported to the Council where a State is seeking to justify those measures on the basis of self-defense) (emphasis added). It might be accurate to characterize the interpretive powers of the Council as, if not necessarily primarily legal, then at least somewhat legal in nature. That contention might accord with the approach of the ICJ in the Namibia advisory opinion. There, the ICJ formed its interpretation of the term “concurring votes of the permanent members” by relying primarily on the practice of the Council (as the competent organ) in combination with the fact that the Council’s practice was then “generally accepted” by Member States and evidences a general practice of the United Nations. See Namibia, Advisory Opinion, above note 176, at 22.
[185]. See Commentary on the Draft Subsequent Agreement Conclusions, above note 65, at 100.
[186]. See U.N. Charter arts. 2(5), 2(7), 24(1), 25, 39–51, 103.
[187]. Peters, Article 24, above note 172, at 828, marginal note 135 (citation omitted); see also The United Nations and International Law, above note 183, at 419, marginal note 12.12 (“The Security Council has the more specific mandate of maintaining peace and security, but it has engaged in influential interpretation of the Charter. It has interpreted and modified Charter provisions on membership and voting. A ‘threat to the peace’ under Article 39 has evolved to include humanitarian crises, and ‘armed attack’ in Article 51 has been applied to terrorism. Military measures that have been taken under Chapter VII differ from what was originally conceived of in Articles 42, 43, and 47 of the UN Charter. It has established criminal tribunals and compensation commissions, and become engaged in territorial administration.”) (citations omitted).
[188]. See Kadelbach, above note 182, at 89, marginal note 47. The ICJ, in the Certain Expenses of the United Nations (Article 17, paragraph 2, of the Charter) advisory opinion, formulated the following position:
In the legal systems of States, there is often some procedure for determining the validity of even a legislative or governmental act, but no analogous procedure is to be found in the structure of the United Nations. Proposals made during the drafting of the Charter to place the ultimate authority to interpret the Charter in the International Court of Justice were not accepted; …. As anticipated in 1945, therefore, each organ must, in the first place at least, determine its own jurisdiction. If the Security Council, for example, adopts a resolution purportedly for the maintenance of international peace and security and if, in accordance with a mandate or authorization in such resolution, the Secretary-General incurs financial obligations, these amounts must be presumed to constitute ‘expenses of the Organization’.
Certain Expenses of the United Nations (Article 17, paragraph 2, of the Charter), Advisory Opinion of July 20, 1962, 1962 I.C.J. Reports, 151, 168 (July 20) (emphasis added). At least in line with that reasoning, the results of a U.N. organ’s interpretation are not formally binding on the other organs. Kadelbach, above note 182, at 89, marginal note 47 (citations omitted). It has been argued that “the Security Council is authorized neither to undertake an authentic interpretation nor to amend the Charter. These powers are incumbent on the members as ‘masters of the treaty’.” Peters, Article 24, above note 172, at 835, marginal note 155.
[189]. Draft CIL Conclusions, above note 88, at 121 (emphasis added).
[190]. Id. (draft conclusion 12, para. 3) (emphasis added).
[191]. Id. at 147. Here, only the practice that is attributed to the Security Council — as an organ of the U.N. Organization — may be relevant in these ways. See id. at 130. The practice of States acting within or in relation to the Security Council remains attributable to the States concerned (not to the Council itself). See id.; see also id. at 147. For their part, Security Council resolutions (or, at least, decisions) seem to fit within the scope of resolutions capable of producing relevant legal effects. Id. at 147. Yet the ILC cautioned that resolutions “adopted by organs … with more limited membership [than the U.N. General Assembly, such as, it can be presumed, the Security Council] may also be relevant, but their weight in identifying a rule of customary international law is likely to be less [than organs with full membership].” Id. (emphasis added). In the context of this particular ILC draft conclusion, one dimension of what may be considered relevant “is that [resolutions of organs of international organizations] may reflect the collective expression of the views of such States: when they purport (explicitly or implicitly) to touch upon legal matters, the resolutions may afford an insight into the attitudes of the member States towards such matters.” Id. at 147 (emphasis added). As with “treaties, resolutions cannot be a substitute for the task of ascertaining whether there is in fact a general practice that is accepted as law (accompanied by opinio juris).” Id. In any event, the ILC exhorted that caution is required “in assessing the weight of the practice of an international organization as part of a general practice.” Id. at 131. As a general rule, “the more directly a practice of an international organization is carried out on behalf of its member States or endorsed by them, and the larger the number of such member States, the greater weight it may have in relation to the formation, or expression, of rules of customary international law.” Id. (emphasis added).
[192]. Id. at 131.
[193]. Id.
[194]. Id. That is in part because it might be argued that the only relevant practice of the Security Council is that which forms part of the practice of the U.N. Organization in the latter’s international relations — and when accompanied, separately, by indications of opiniones juris of enough States — that gives rise to, or attests to, certain rules of customary international law. Id.
[195]. See above note 186 and the accompanying text.
[196]. See Olivier Corten, La participation du Conseil de sécurité à l’élaboration, à la cristallisation ou à la consolidation de règles coutumières, 37 Revue Belge de Droit Int’l 552, 556 (2004) (“Dans le domaine de l’interdiction du recours à la force, par exemple, le Conseil de sécurité peut condamner un Etat en qualifiant incidemment son action d’illicite, et ce en rejetant ses arguments juridiques. On peut alors se trouver devant un précédent qui, combiné à d’autres, peut être pris en compte pour préciser le sens de la prohibition de l’interdiction du recours à la force dans les relations entre Etats à partir d’une pratique du Conseil de sécurité.”) (citations omitted).
[197]. See id. at 557 (“[L]es nombreux débats qui ont eu lieu en son sein ou dans d’autres cénacles méritentils toute l’attention, dans la mesure où ils révèlent des prises de position juridiques très claires en ce domaine.”) (citation omitted).
[198]. See id. at 553 (“Ce n’est que dans une mesure limitée que le Conseil peut prétendre contribuer à l’émergence, à la cristallisation ou à la consolidation d’une règle coutumière de droit international général.”). Along that line of reasoning, the Security Council has also and separately been characterized as participating in a “law-making exercise” that, among other things, “produces quasi-legislative effects through the mere affirmation and concretization of legal standards, partly through an impact on customary international law.” Nico Krisch, Introduction to Chapter VII: The General Framework, in II The Charter of the United Nations: A Commentary 1252, marginal note 32 (Bruno Simma, Daniel-Erasmus Khan, Georg Nolte, & Andreas Paulus eds., Nikolai Wessendorf assistant ed., 3d ed., 2012).
[199]. Draft CIL Conclusions, above note 88, at 120 (draft conclusion 6, para. 1) (with respect to States).
[200]. Id. at 133 (emphasis added).
[201]. Id. at 120 (draft conclusion 10, para. 3) (with respect to States).
[202]. See Olivier Corten, La participation du Conseil de sécurité, above note 196, at 553. In any event, arguably the practice of the Security Council in this area (as in other areas) may not, in itself, be decisive in respect of a particular case. See id. at 556–57.
[203]. U.N. Charter art. 51, second sentence (emphasis added). On the reporting requirement, see James A. Green, The Article 51 Reporting Requirement for Self-Defense Actions, 55 Virginia J. Int’l L. 563 (2015); D. W. Greig, Self-Defense and the Security Council: What Does Article 51 Require?, 40 Int’l & Comparative L. Quarterly 366 (1991); Jean Combacau, The Exception of Self-Defense in U.N. Practice, in The Current Legal Regulation of the Use of Force 9–38 (Antonio Cassese ed., 1986).
[204]. Military and Paramilitary Activities, Judgment, above note 148, at 105.
[205]. See Annex.
[206]. In response to (among other things) Armenia, S/26328 (Aug. 18, 1993), see U.N. Security Council, Presidential Statement S/26326 (Aug. 18, 1993), at 1 (“The Security Council expresses its serious concern at the deterioration of relations between the Republic of Armenia and the Azerbaijani Republic and at the tensions between them. The Council calls upon the Government of Armenia to use its influence to achieve compliance by the Armenians of the Nagorny Karabakh region of Azerbaijan with Council resolutions 822 (1993) and 853 (1993).”). As another example, in response to (among other things) Croatia, S/1995/647 (Aug. 4, 1995), see U.N. Security Council, Presidential Statement S/PRST/1995/38 (Aug. 4, 1995), at 1 (“The Security Council is deeply concerned at the resumption of hostilities in and around the Republic of Croatia. The Council recalls the statement by its President of 3 August 1995. It strongly deplores the decision by the Croatian Government to launch a broad military offensive, thereby unacceptably escalating the conflict, with the risk of further consequent attacks by whatever party, and demands that all military action cease immediately and that there be full compliance with all Council resolutions including resolution 994 (1995).”).
[207]. S/PV.2611 (Oct. 2, 1985), Israel, at 5.
[208]. U.N. Security Council, resolution 573 (1985), S/RES/573(1985), Oct. 4, 1985, OPs 1–2. See also, in response to (among other things) Israel, S/3525 (Jan. 3, 1956), see U.N. Security Council, resolution 111 (1956), S/RES/111(1956), Jan. 19, 1956, OP 3 (“Condemns the attack of 11 December 1955 [by Israel regular army forces against Syrian regular army forces on Syrian territory] as a flagrant violation of the cease-fire provisions of its resolution of 15 July 1948, of the terms of the General Armistice Agreement between Israel and Syria, and of Israel’s obligations under the Charter” (adopted unanimously); in response to (among other things) S/PV.1320 (Nov. 16, 1966), Israel, at 14, see U.N. Security Council, resolution 228 (1966), S/RES/228(1966), Nov. 25, 1966, OP 2 (“Censures Israel for this large-scale military action [that is, ‘the grave Israel military action which took place in the southern Hebron area of 13 November 1966’] in violation of the United Nations Charter and of the General Armistice Agreement between Israel and Jordan” (14–0–1)); in respect to (among other things) Israel, S/8470 (Mar. 18, 1968), at 3, U.N. Security Council, resolution 248 (1968), S/RES/248(1968), Mar. 24, 1968, OPs 2–3 (“2. Condemns the military action launched by Israel in flagrant violation of the United Nations Charter and the cease-fire resolutions; 3. Deplores all violent incidents in violation of the cease-fire and declares that such actions of military reprisal and other grave violations of the cease-fire cannot be tolerated and that the Security Council would have to consider further and more effective steps as envisaged in the Charter to ensure against repetition of such acts” (adopted unanimously)); in response to (among other things) Israel, S/9089 (Mar. 17, 1969) and S/PV.1466 (Mar. 27, 1969), Israel, at 8, see U.N. Security Council, resolution 265 (1969), S/RES/265(1969), Apr. 1, 1969, OP 3 (“Condemns the recent premeditated air attacks launched by Israel on Jordanian villages and populated areas in flagrant violation of the United Nations Charter and the cease-fire resolutions, and warns once again that if such attacks were to be repeated the Security Council would have to meet to consider further and more effective steps as envisaged in the Charter to ensure against repetition of such attacks.” (11-0-4)); in response to (among other things) S/9387 (Israel, Aug. 12, 1969), see U.N. Security Council, resolution 270 (1969), S/RES/270(1969), Aug. 26, 1969, OP 1 (“Condemns the premeditated air attack by Israel on villages in southern Lebanon in violation of its obligations under the Charter and Security Council resolutions” (adopted without vote)); in response to (among other things) S/PV.1537 (May 12, 1970), Israel, at 4, see U.N. Security Council, resolution 280 (1970), S/RES/280(1970), May 12, 1970, inter alia, OP 2 (“Condemns Israel for its premeditated military action in violation of its obligations under the Charter of the United Nations” (11–0–4)); see also U.N. Security Council, resolution 279 (1970), S/RES/279(1970), May 12, 1970: “Demands the immediate withdrawal of all Israeli armed forces from Lebanese territory.” (unanimous); in response to (among other things) S/PV.2280 (June 12, 1981), Israel, at 8, see U.N. Security Council, resolution 487 (1981), S/RES/487(1981), June 19, 1981, OP 1 (“Strongly condemns the military attack by Israel in clear violation of the Charter of the United Nations and the norms of international conduct” (15-0-0)).
[209]. E.g., in response to (among other things) France, S/4864 (July 21, 1961), at 5, see U.N. Security Council, resolution 164 (1961), S/RES/164(1961), July 22, 1961, OPs 1–2 (“1. Calls for an immediate cease-fire and a return of all armed forces to their original position; 2. Decides to continue the debate” (10-0-0)); in response to (among other things) United Kingdom, S/15119 (May 25, 1982), see U.N. Security Council, resolution 505 (1982), S/RES/505(1982), May 26, 1982, OP 4 (“Requests the Secretary-General to enter into contact immediately with the parties with a view to negotiating mutually acceptable terms for a cease-fire, including, if necessary, arrangements for the dispatch of United Nations observers to monitor compliance with the terms of the cease-fire” (15-0-0); in response to (among other things) United States, S/21492 (Aug. 10, 1990), United Kingdom, S/21501 (Aug. 13, 1990), and United States, S/21537 (Aug. 16, 1990), see U.N. Security Council, resolution 665 (1990), S/RES/665(1990), Aug. 25, 1990, OP 1 (“Calls upon those Member States co-operating with the Government of Kuwait which are deploying maritime forces to the area to use such measures commensurate to the specific circumstances as may be necessary under the authority of the Security Council to halt all inward and outward maritime shipping, in order to inspect and verify their cargoes and destinations and to ensure strict implementation of the provisions related to such shipping laid down in resolution 661 (1990)” (13-0-2) and U.N. Security Council, resolution 678 (1990), S/RES/678(1990), Nov. 29, 1990, OP 2 (“Authorizes Member States co-operating with the Government of Kuwait, unless Iraq on or before 15 January 1991 fully implements, ... the above-mentioned resolutions, to use all necessary means to uphold and implement resolution 660 (1990) and all subsequent relevant resolutions and to restore international peace and security in the area” (12-2-1)); in response to (among other things) Kazakhstan, Kyrgyzstan, Russia, and Tajikistan, S/26290 (Aug. 11, 1993), at 2, see Note by the President of the Council S/26341 (Aug. 23, 1993), at 1 (“The Council expresses its deep concern at the continuing violence and armed conflict in Tajikistan, at the escalating crisis along the Tajik-Afghan border, and at the risk of the conflict threatening the peace and stability of Central Asia and beyond. [¶] The Council stresses the urgent need for the cessation of all hostile actions on the Tajik-Afghan border....”); arguably in response to (among other things) United States, S/2014/695 (Sept. 23, 2014), United Kingdom, S/2014/851 (Nov. 26, 2014), United Kingdom, S/2015/688 (Sept. 8, 2015), and France, S/2015/745 (Sept. 9, 2015), see U.N. Security Council, resolution 2249 (2015), S/RES/2249(2015), Nov. 20, 2015, PP v, OP 5 (“Determining that, by its violent extremist ideology, its terrorist acts, its continued gross systematic and widespread attacks directed against civilians, abuses of human rights and violations of international humanitarian law, including those driven on religious or ethnic ground, its eradication of cultural heritage and trafficking of cultural property, but also its control over significant parts and natural resources across Iraq and Syria and its recruitment and training of foreign terrorist fighters whose threat affects all regions and Member States, even those far from conflict zones, the Islamic State in Iraq and the Levant (ISIL, also known as Da’esh), constitutes a global and unprecedented threat to international peace and security, .... [5] Calls upon Member States that have the capacity to do so to take all necessary measures, in compliance with international law, in particular with the United Nations Charter, as well as international human rights, refugee and humanitarian law, on the territory under the control of ISIL also known as Da’esh, in Syria and Iraq, to redouble and coordinate their efforts to prevent and suppress terrorist acts committed specifically by ISIL also known as Da’esh as well as ANF, and all other individuals, groups, undertakings, and entities associated with Al Qaeda, and other terrorist groups, as designated by the United Nations Security Council, and as may further be agreed by the International Syria Support Group (ISSG) and endorsed by the UN Security Council, pursuant to the Statement of the International Syria Support Group (ISSG) of 14 November, and to eradicate the safe haven they have established over significant parts of Iraq and Syria” (15–0–0)).
[210]. But see, e.g., below notes 217–222 and the accompanying text; see also Remarks by Patrick Luna, 112 Am. Soc’y Int’l L. Proc. 50 (2018).
[211]. See Annex.
[212]. See The Procedure of the UN Security Council (Loraine Sievers & Sam Daws eds., 4th ed., 2014), Online Supplement, Mar. 10, 2018, https://www.scprocedure.org/chapter-7-section-12b, permalink: https://perma.cc/6UK5-HFT5 (“The Mexican representative queried whether communications transmitted pursuant to Article 51 are published or referenced in the UN Journal. In fact, … each has been given a document symbol and published as an official Security Council document.)
[213]. Id.
[214]. As noted in the Annex, it is not necessarily clear whether only written communications may count or whether verbal statements may (also) satisfy the reporting requirement laid down in the second sentence of article 51 of the U.N. Charter. So far as the authors of the catalogue are aware, the Security Council has never directly and authoritatively addressed that specific question as such, nor have other U.N. Organs or U.N. Member States writ large. The catalogue presumes that both written and verbal communications may count and therefore includes both types of communications. See Annex.
[215]. Security Council Meetings in 2018 (undated), http://research.un.org/en/docs/sc/quick/meetings/2018, permalink: https://perma.cc/TV7S-49H5.
[216]. See Turkey, S/2018/53 (Jan. 22, 2018), at 1–2; Syria, S/2018/141 (Feb. 26, 2018), at 1; Iran, S/2018/891 (Oct. 3, 2018), at 1; Turkey, S/2018/1022 (Nov. 15, 2018).
[217]. El Salvador, Measures to Eliminate International Terrorism, Statement on behalf of the Community of Latin American and Caribbean States (CELAC), Oct. 2, 2017, (unpaginated) 7, http://statements.unmeetings.org/media2/16152279/el-salvador-on-behalf-of-celac-1.pdf, permalink: https://perma.cc/V2FW-ZB4B.
[218]. Id.
[219]. See S/PV.8175 (Feb. 6, 2018), Brazil, at 24.
[220]. Id. See also Remarks by Patrick Luna, above note 210, at 54–55 (legal adviser of Brazil stating the following: “It has been argued, also, that the rest of the membership has been silent and maybe that this silence could be interpreted as acquiescence, and this is also not a fair point for two reasons. One, it is not true that the rest of the membership has remained silent. You will find, for instance, a non-aligned movement statement that has been reiterating the position that Article 51 is not to be rewritten or reinterpreted, and, of course, the NAM [Non-Aligned Movement] compromises more than 120 member states. You would find some Latin American countries, like Brazil and Mexico, stating on the record, in the General Assembly, and in the Security Council, that they have problems with, for instance, the unwilling and unable doctrine. And even in academia you will find this kind of divergence, and I would like to point to the plea against the abusive invocation of self-defense as a response to terrorism that was initiated by Professor Olivier Corten and signed by more than 240 international lawyers and academics from thirty-six different countries.”); Alex Moorehead, Brazil’s Robust Defense of the Legal Prohibition on the Use of Force and Self Defense, Just Security, Apr. 20, 2018, https://www.justsecurity.org/55126/brazils-robust-defense-legal-prohibition-force/, permalink: https://perma.cc/BYK2-AJKW.
[221]. Pablo Arrocha Olabuenaga, An Insider’s View of the Life-Cycle of Self-Defense Reports by U.N. Member States, Just Security, Apr. 2, 2019, https://www.justsecurity.org/63415/an-insiders-view-of-the-life-cycle-of-self-defense-reports-by-u-n-member-states/, permalink: https://perma.cc/45N7-PZZV.
[222]. Id.
[223]. See below notes 237–39 and the accompanying text.
[224]. See Annex.
[225]. U.N. General Assembly, resolution 685 (VII) (“Ways and means for making the evidence of customary international law more readily available”), Dec. 5, 1952.
[226]. U.N. Secretary-General, A/73/190 (“Repertory of Practice of United Nations Organs and Repertoire of the Practice of the Security Council: Report of the Secretary-General”), July 19, 2019, para. 18. In its most recent relevant resolution, the General Assembly called upon the Secretary-General, in undertaking the Repertoire (and its Supplements), to continue to follow the modalities outlined in paragraphs 102 to 106 of his report of September 18, 1952. U.N. General Assembly, resolution 73/206 (“Report of the Special Committee on the Charter of the United Nations and on the Strengthening of the Role of the Organization”), A/RES/73/206, OP 17, Dec. 20, 2018. According to the General Assembly, the quality of the Repertoire and its Supplements is the responsibility of the Secretary-General. Id.
[227]. See U.N. Security Council, Repertoire of the Practice of the Security Council, https://www.un.org/securitycouncil/content/repertoire/structure; permalink: https://perma.cc/4Q9U-UEXB. Advanced versions of drafts of the 19th Supplement (covering 2014–2015) and the 20th Supplement (covering 2016–2017) of the Repertoire are available online. Id.
[228]. See Annex.
[229]. U.N. General Assembly, resolution 796 (VIII) (“Publication of documents concerning the drafting and application of the Charter: Preparatory work with regard to the possible holding of a General Conference of the Members of the United Nations in accordance with Article 109 of the Charter”), A/RES/796/(VIII), Nov. 27, 1953.
[230]. See, e.g., A/RES/73/206, above note 226, at OP 2. The quality of the Repertory (and Supplements thereto) is, according to the General Assembly, the responsibility of the Secretary-General. See id. at OP 17.
[231]. See A/73/190, above note 226, at OPs 3–5. The General Assembly has noted part of the backlog with concern. See, most recently, A/RES/73/206, above note 226, OP 16. As of
July 19, 2018, the status of publications of the Repertory and Supplements thereto was reportedly as follows:
30 volumes have been published and 14 have been finalized and submitted for translation and publication. Consequently, from among the 57 volumes of which the publication as a whole (original Repertory and Supplements Nos. 1 to 11 thereto) should consist, work remains to be completed on 13, 6 of which pertain to Supplement No. 11 (2010–2015), on which work has begun (…), and 4 to Supplement No. 10 (2000–2009), which are at different stages of preparation (…). The other three volumes on which work remains to be completed correspond to volume III of Supplements Nos. 7 to 9 [(1985–1999)].
A/73/190, above note 226, at OP 8. Footnotes accompanying the first sentence of the excerpt indicate that the 30 volumes that have been published constitute “Repertory and Supplements Nos. 1 to 6 (1946–1984), for a total of 27 volumes, volumes V and VI of Supplement No. 7 (1985–1988) and volume I of Supplement No. 10 (2000–2009).” and that the 14 volumes that have been finalized and submitted for translation and publication constitute “Volumes I, II and IV of Supplement No. 7 (1985–1988), volumes I, II, IV, V and VI of Supplements Nos. 8 (1989–1994) and 9 (1995–1999) and volume II of Supplement No. 10 (2000–2009).” Id. at nn.1, 2.
[232]. See Annex.
[233] See A/41/41 (“Report of the Special Committee on Enhancing the Effectiveness of the Principle of Non-Use of Force in International Relations”), Mar. 13, 1986, at 12, para. 46.
[234]. See id. at 12, para. 47 (stating that “[t]hese [five] ideas elicited a favourable response from some delegations but gave rise to doubts on the part of others. ... On point (c) [concerning the idea of authorizing the Secretary-General, acting on behalf of the Security Council, to enquire of a nation apparently having used force if it wished to assert that its actions were taken in self-defence], the remark was made that the Security Council was probably the only organ which could undertake the proposed task. Furthermore, each situation was sui generis, which was the reason why the Security Council enjoyed discretionary powers in discharging its functions in the light of all the circumstances of the case. The Committee should, it was stated, refrain from venturing into the political field and focus on the formulation of provisions of a legal nature.”).
[235]. See U.N. General Assembly, resolution 42/22 (“Declaration on the Enhancement of the Effectiveness of the Principle of Refraining from the Threat or Use of Force in International Relations prepared by the Special Committee”), A/RES/42/22, Nov. 18, 1987.
[236]. See U.N. General Assembly, resolution 3499 (XXX) (“Special Committee on the Charter of the United Nations and on the Strengthening of the Role of the Organization”), A/RES/3499(XXX), Dec. 15, 1975, para. 1. On December 18, 2015, the General Assembly, with respect to the mandate of the Committee, “[r]equest[ed] the Special Committee ... [t]o continue its consideration of all proposals concerning the question of the maintenance of international peace and security in all its aspects in order to strengthen the role of the United Nations and, in this context, to consider other proposals relating to the maintenance of international peace and security already submitted or which may be submitted to the Special Committee....” U.N. General Assembly, resolution 70/117 (“Report of the Special Committee on the Charter of the United Nations and on the Strengthening of the Role of the Organization”), A/RES/70/117, Dec. 18, 2015, para. 3(a).
[237]. A/73/33 (“Report of the Special Committee on the Charter of the United Nations and on the Strengthening of the Role of the Organization”), Mar. 1, 2018, para. 83.
[238]. Id.
[239]. See id. at para. 84; Intervención de México en el debate de la Sexta Comisión sobre el Informe del Comité Especial de la Carta de las Naciones Unidas en el marco de sesiones de la 73a Asamblea General de la ONU, Oct. 12, 2018, https://mision.sre.gob.mx/onu/index.php/eventos/800-intervencion-de-mexico-en-el-debate-de-la-sexta-comision-sobre-el-informe-del-comite-especial-de-la-carta-de-las-naciones-unidas-en-el-marco-de-sesiones-de-la-73a-asamblea-general-de-la-onu, permalink: https://perma.cc/U8AR-NX7U; A/AC.182/2019/L.10, paras. 8–9.
[240]. See International Law Association, Use of Force Comm., Final Report on Aggression and Use of Force, 2018, 15, http://www.ila-hq.org/images/ILA/DraftReports/DraftReport_UseOfForce.pdf, permalink: https://perma.cc/F2VG-WDTP.
[241]. Id. The other questions were formulated as follows: what steps must be taken before any such right (if it is established) can be exercised; whether force against the non-state actor can be distinguished from force against the territorial/host State; whether the territorial/host State might be in violation of international law due to the activities of the non-state actor; and if so, whether this justifies force against the host State itself. Id.
[242]. U.N. Charter art. 51, first sentence (emphasis added). We do not take a position here on whether or not the content of this treaty provision concerning “armed attack” is reflective of customary international law.
[243]. International Law Association, Use of Force Comm., above note 240, at 15–16.
[244]. See José Luis Aragón Cardiel, Amanda Davis, & Lauranne Macherel, Modern Self-defense in Practice: Two Case Scenarios, 2 HRLR Online 1, 5 n.19 (2018) (citation omitted).
[245]. See Michael Byers, The Intervention in Afghanistan—2001–, in The Use of Force in International Law: A Case-based Approach 634 (Tom Ruys & Olivier Corten eds., Alexandra Hofer assistant ed., 2018); Frederic Kirgis, Israel’s Intensified Military Campaign Against Terrorism, 6 ASIL Insight, No. 19, Dec. 5, 2001, https://www.asil.org/insights/volume/6/issue/19/israels-intensified-military-campaign-against-terrorism, permalink: https://perma.cc/V3PJ-3JVH.
[246]. See Cardiel et al., above note 244, at 16–17 (citations omitted); Byers, above note 245, at 634.
[247]. See Cardiel et al., above note 244, at 5 n.19 (citation omitted); Michael P. Scharf, How the War Against ISIS Changed International Law, 48 Case Western Reserve J. Int’l L. 15, 50 (2016) (citations omitted).
[248]. See Monica Hakimi, Defensive Force against Non-State Actors: The State of Play, 91 Int’l L. Stud. 1, 14 (2015).
[249]. See Scharf, above note 247, at 50 (citations omitted).
[250]. See Hakimi, above note 248, at 14; Tom Ruys, Quo Vadit Jus ad Bellum?: A Legal Analysis of Turkey’s Military Operations against the PKK in Northern Iraq, 9 Melb. J. Int’l L. 334, 344 (2008); Scharf, above note 247, at 50 (citation omitted).
[251]. See Scharf, above note 247, at 50 (citations omitted).
[252]. See id. at 51 (citation omitted).
[253]. See id. (citation omitted).
[254]. See id. (citation omitted).
[255]. See Cardiel et al., above note 244, at 16–17 (citations omitted).
[256]. In addition to the caveats elaborated in the Annex that pertain to the entire catalogue, the following additional caveat should be borne in mind: in respect of certain identified “article 51 communications,” it is not necessarily clear whether or not the State submitting the report intended to attribute the allegedly self-defense-generative conduct of the relevant non-state actors (for example, purported “armed attacks” by alleged “terrorists” or “irregular forces”) to a State (for example, to the State from whose territory those actors are allegedly launching actions giving rise to a purported exercise of the right of self-defense of the victim State) or to otherwise seek to engage the responsibility of the territorial/host (or another) State (for example, on the grounds that the other State allegedly acquiesced in or otherwise tolerated self-defense-generative conduct of the non-state actors). The catalogue of “article 51 communications” on which we draw distinguishes between three sets of categories with respect to the nature of the authors of the alleged threat giving rise to the claim of self-defense: (1) A State (or States); (2) a State (or States) and non-state actors; or (3) non-state actors. See Annex. The practice described in this part of the paper is drawn only from categories (2) and (3) of the catalogue.
[257]. See Belgium, S/2016/523 (June 9, 2016) (“ISIL has occupied a certain part of Syrian territory over which the Government of the Syrian Arab Republic does not, at this time, exercise effective control. In the light of this exceptional situation, States that have been subjected to armed attack by ISIL originating in that part of the Syrian territory are therefore justified under Article 51 of the Charter to take necessary measures of self-defence. Exercising the right of collective self-defence, Belgium will support the military measures of those States that have been subjected to attacks by ISIL.”) (emphasis added).
[258]. See Iran, S/25843 (May 26, 1993), at 1 (“During the past few weeks, bands of armed and organized terrorist mercenaries have engaged in trans-border military attacks against and sabotage in Iranian border provinces. These bands, whose headquarters and military bases are located in Iraq where military training, financial and logistical support and intelligence services are provided to them, have admittedly perpetrated terrorist activities inside Iran, resulting in martyrdom of civilians and military personnel and in infliction of damages to Iranian oil installations. [¶] … [¶] In response to these armed attacks from inside Iraq and in accordance with Article 51 of the Charter of the United Nations, … the fighter jets of the Islamic Republic Air Force carried out a brief, necessary and proportionate operation against the military bases of the terrorist group where the recent armed attacks against and incursions into Iranian territory had originated.”); Iran, S/1994/1273 (Nov. 10, 1994), at 1 (“Over the past weeks, these terrorist groups have intensified their bombing campaigns and armed attacks against civilians and oil installations in the Islamic Republic of Iran resulting in the martyrdom of a number of Iranian nationals and material damages.”); Iran, S/1996/602 (July 29, 1996) (“Consequently, in recent weeks transborder armed attacks and sabotage operations by terrorist groups against Iranian border towns, originating from Iraqi territory, have been intensified and escalated.”) (emphasis added).
[259]. See, e.g., Israel, S/9387 (Aug. 12, 1969) (“It is generally known that Lebanon harbours on its territory, and particularly in its southern region bordering with Israel, considerable concentrations of irregular forces which are engaged in waging terror warfare against Israel. [¶] In the face of these attacks Israel was compelled to take, on 11 August 1969, action in self-defence against the terror encampments on the slopes of Mount Hermon. [¶] An official communique of the terror organizations command broadcast last night over Radio Damascus confirmed that the Israeli action was directed against bases of the terror organizations. [¶] In view of the gravity of the armed attacks perpetrated against Israel from Lebanese territory, I have the honour, on instructions from my Government to request you to convene an urgent meeting of the Security Council.”) (emphasis added).
[260]. See Germany, S/2015/946 (Dec. 10, 2015) (“ISIL has carried out, and continues to carry out, armed attacks against Iraq, France, and other States. These States have acted, and continue to act, by taking measures of self-defence.”) (emphasis added).
[261]. See Kazakhstan, Kyrgyzstan, Russia, Tajikistan, and Uzbekistan, S/26290 (Aug. 11, 1993), at 4 (“Particularly alarming are the actions by fighters from the Tajik opposition and the individual Afghan armed groups that support them and the systematic incursions into the territory of Tajikistan, which have resulted in an increasing number of victims among the civilian population, frontier guards and other military personnel. [¶] The heads of State proclaim the following: ... If armed attacks from the outside continue, reciprocal and commensurate measures will be taken to stop them, as envisaged by the Treaty on Collective Security concluded between the countries of the Commonwealth of Independent States and by bilateral agreements with Tajikistan, and in accordance with the right of individual or collective self-defence provided for in Article 51 of the Charter of the United Nations.”) (emphasis added).
[262]. See S/PV.1516 (Dec. 4, 1969), Portugal, at 9 (“It is common knowledge that anti-Portuguese organizations operate from Senegal and from the Republic of Guinea against Portuguese Guinea. For several years now those organizations have been carrying out armed attacks against the peaceful rural populations of the Portuguese territory on the other side of the frontier.”) (emphasis added).
[263]. See United Kingdom, S/2015/928 (Dec. 3, 2015) (“On 21 August 2015, armed forces of the United Kingdom of Great Britain and Northern Ireland carried out a precision air strike against an ISIL vehicle in which a target known to be actively engaged in planning and directing imminent armed attacks against the United Kingdom was travelling. … [¶] As reported in our letter of 25 November 2014, ISIL is engaged in an ongoing armed attack against Iraq, and therefore action against ISIL in Syria is lawful in the collective self-defence of Iraq.”) (emphasis added).
[264]. See United States, S/9854 (July 1, 1970), at 1–2 (“Nevertheless, North Viet-Namese and Viet-Cong forces remain in Cambodia in pursuance of their armed attack against the Republic of Viet-Nam. Consequently, the United States will conduct – with the approval of the Cambodian Government – air interdiction missions against North Viet-Namese forces and their efforts to move supplies and personnel through Cambodia towards the Republic of Vietnam and to re-establish base areas for use in the conflict in Viet-Nam. These air interdiction missions are appropriate and limited measures of collective self-defence against the continuing armed attack against the Republic of Viet-Nam being carried on in part from Cambodian territory.”) (emphasis added); United States, S/1998/780 (Aug. 20, 1998), at 1 (“In accordance with Article 51 of the Charter of the United Nations, I wish, on behalf of my Government, to report that the United States of America has exercised its right of self-defence in responding to a series of armed attacks against United States embassies and United States nationals. [¶] My Government has obtained convincing information from a variety of reliable sources that the organization of Usama Bin Ladin is responsible for the devastating bombings on 7 August 1998 of the United States embassies in Nairobi and Dar Es Salaam.”) (emphasis added); United States, S/2001/946 (Oct. 7, 2001), at 1 (“In accordance with Article 51 of the Charter of the United Nations, I wish, on behalf of my Government, to report that the United States of America, together with other States, has initiated actions in the exercise of its inherent right of individual and collective self-defence following the armed attacks that were carried out against the United States on 11 September 2001. [¶] On 11 September 2001, the United States was the victim of massive and brutal attacks in the states of New York, Pennsylvania and Virginia. These attacks were specifically designed to maximize the loss of life; they resulted in the death of more than 5,000 persons, including nationals of 81 countries, as well as the destruction of four civilian aircraft, the World Trade Center towers and a section of the Pentagon. Since 11 September, my Government has obtained clear and compelling information that the Al-Qaeda organization, which is supported by the Taliban regime in Afghanistan, had a central role in the attacks.”) (emphasis added); United States, S/2014/417 (June 18, 2014) (“On behalf of my Government, I wish to report that the United States of America has taken action in Libya to capture Ahmed Abu Khattalah, a senior leader of the Libyan militant group Ansar al-Sharia-Benghazi in Libya. … [¶] As is well known, the United States Temporary Mission Facility and Annex in Benghazi, Libya, were attacked in September 2012, and the United States Ambassador to Libya and three other Americans were killed. Following a painstaking investigation, the United States Government ascertained that Ahmed Abu Khattalah was a key figure in those armed attacks. The investigation also determined that he continued to plan further armed attacks against United States persons.”) (emphasis added).
[265]. See also above note 256.
[266]. See Australia, S/2001/1104 (Nov. 23, 2001), at 1 (“In accordance with Article 51 of the Charter of the United Nations, I am writing on behalf of my Government to report to the Security Council that Australia has taken measures in the exercise of the inherent right of individual and collective self-defence following the armed attacks against the United States of America on 11 September 2001. [¶] As you are aware, Australia has strongly condemned those responsible for the September terrorist attacks.”) (emphasis added); Australia, S/2015/693 (Sept. 9, 2015) (“Article 51 of the Charter of the United Nations recognizes the inherent right of States to act in individual or collective self-defence where an armed attack occurs against a Member of the United Nations. States must be able to act in self-defence when the Government of the State where the threat is located is unwilling or unable to prevent attacks originating from its territory. The Government of Syria has, by its failure to constrain attacks upon Iraqi territory originating from ISIL bases within Syria, demonstrated that it is unwilling or unable to prevent those attacks.”) (emphasis added).
[267]. See Canada, S/2001/1005 (Oct. 24, 2001) (“In accordance with Article 51 of the Charter of the United Nations, I wish on behalf of my Government to report to the Security Council on measures that Canada has initiated following the armed attacks in the United States on 11 September 2001. Those attacks, which were the subject of Security Council resolutions 1368 (2001) of 12 September 2001 and 1373 (2001) of 28 September 2001, resulted in the deaths of thousands of citizens from many countries, including Canada. [¶] As announced by Canada’s Prime Minister, the Right Honourable Jean Chrétien, on 7 October 2001, Canada is deploying naval ships, surveillance and transport airplanes, military personnel and other assets. Our actions are directed against Osama bin Laden’s al-Qa‘ida terrorist organization and the Taliban regime that is supporting it.”) (emphasis added).
[268]. See Germany, S/2001/1127 (Nov. 29, 2001) (“In accordance with Article 51 of the Charter of the United Nations, I wish on behalf of my Government to report to the Security Council on measures that the Federal Republic of Germany has initiated following the armed attacks that were carried out against the United States on 11 September 2001. [¶] As approved by the German Federal Parliament on 16 November 2001, Germany is providing nuclear, biological and chemical (NBC) defence units, medical units, specialized units, air-transport capacities, naval forces, including navy aviation, and necessary support units. These measures are solely directed against the terrorist network of Bin Laden, Al-Qaida, and those harbouring and supporting it.”) (emphasis added).
[269]. See the Netherlands, S/2001/1171 (Dec. 6, 2001) (“In accordance with Article 51 of the Charter of the United Nations, I wish on behalf of my Government to report to the Security Council on measures that the Kingdom of the Netherlands has taken following the armed attacks against the United States of America on 11 September 2001.”) (emphasis added).
[270]. See New Zealand, S/2001/1193 (Dec. 18, 2001) (“In accordance with Article 51 of the Charter of the United Nations, I am writing on behalf of my Government to report that New Zealand has joined other States in the exercise of its inherent right of individual and collective self-defence following the terrorist attacks in the United States of America on 11 September 2001. [¶¶] ... New Zealand’s military contribution has been employed in support of military operations directed against Osama bin Laden and the Qaeda terrorist organization, and the Taliban which supported and harboured them.”) (emphasis added).
[271]. See Australia, S/2015/693 (Sept. 9, 2015) (“Article 51 of the Charter of the United Nations recognizes the inherent right of States to act in individual or collective self-defence where an armed attack occurs against a Member of the United Nations. States must be able to act in self-defence when the Government of the State where the threat is located is unwilling or unable to prevent attacks originating from its territory. The Government of Syria has, by its failure to constrain attacks upon Iraqi territory originating from ISIL bases within Syria, demonstrated that it is unwilling or unable to prevent those attacks. [¶] In response to the request for assistance by the Government of Iraq, Australia is therefore undertaking necessary and proportionate military operations against ISIL in Syria in the exercise of the collective self-defence of Iraq.”) (emphasis added).
[272]. See Denmark, S/2016/34 (Jan. 13, 2016) (“... Denmark, as called for by the Council in its resolution 2249 (2015) and in response to the request by the Government of Iraq, is taking necessary and proportionate measures against the so-called Islamic State in Iraq and the Levant (ISIL, also known as Da’esh) in Syria in exercise of the inherent right of collective self-defence as part of international efforts led by the United States of America.”) (emphasis added).
[273]. See Iran, S/1996/602 (July 29, 1996) (“In response to these encroachments by terrorist armed groups and in accordance with its inherent right of self-defence enshrined in Article 51 of the Charter, the Islamic Republic of Iran took immediate and proportional measures, which were necessary for curbing and suppressing such aggressive activities. The details of these operations, which have already been concluded, are as follows: On 28 July 1996, the Iranian defence forces pursued the retreating armed groups that attacked civilian targets in the border towns of Piranshahr, Mahabad and Oroumiyeh, and targeted their training camps in Iraq.”) (emphasis added); Iran, S/1999/781 (July 12, 1999), at 2 (“In pursuance of this policy and in the exercise of its right of self-defence under Article 51 of the Charter, the concerned authorities of the Islamic Republic of Iran targeted a well-known active terrorist camp, located in the territory of Iraq, on 10 June 1999. This proportionate action was a necessary defensive measure against the perpetrators of the terrorist crimes that had already been carried out against Iran and its citizens. It also aimed to prevent further recurrence of similar terrorist operations which were being planned and organized at the very same terrorist installations inside Iraq.”) (emphasis added).
[274]. See Israel, S/2010/21 (Jan. 13, 2010) (“Following this escalation in attacks, Israel responded militarily in exercise of its right of self-defence under Article 51 of the Charter of the United Nations. The Israeli response included the precision targeting of a group of terrorists who were preparing to launch additional rockets into Israel, the targeting of a weapons production facility in Tel Hawa, in the Gaza Strip, as well as the destruction of tunnels used to smuggle illegal arms into Gaza. [¶] Israel will continue to take the necessary and appropriate measures in self-defence to confront any such terrorist attacks and activities. The Government of Israel is determined to ensure that the situation in southern Israel does not return to the status quo ante of December 2008.”) (emphasis added).
[275]. See the Netherlands, S/2016/132 (Feb. 10, 2016) (“In accordance with Article 51 of the Charter of the United Nations, I am writing to report to the Security Council that the Kingdom of the Netherlands is taking necessary and proportionate measures against the so-called Islamic State in Iraq and the Levant (ISIL, also known as Da’esh) in Syria in the exercise of the inherent right of collective self-defence of Iraq.”) (emphasis added).
[276]. See Norway, S/2016/513 (June 3, 2016) (“... Norway is taking necessary and proportionate measures against the terrorist organization Islamic State in Iraq and the Levant (ISIL, also known as Da’esh) in Syria in the exercise of the right of collective self-defence.”) (emphasis added).
[277]. See Turkey, S/2015/563 (July 24, 2015), at 1 (“Individual and collective self-defence is our inherent right under international law, as reflected in Article 51 of the Charter of the United Nations. [¶] On this basis, Turkey has initiated necessary and proportionate military actions against Daesh in Syria, including in coordination with individual members of the Global Coalition, in order to counter the terrorist threat and to safeguard its territory and citizens.”) (emphasis added).
[278]. See United Kingdom, S/2014/851 (Nov. 26, 2014) (reporting that the United Kingdom “is taking measures in support of the collective self-defence of Iraq as part of international efforts led by the United States. [¶] These measures are in response to the request by the Government of Iraq for assistance in confronting the attack by the Islamic State in Iraq and the Levant (ISIL) on Iraq, contained in its letter to the President of the Security Council of 20 September 2014 (S/2014/691). The United Kingdom fully supports these international efforts, whose purpose is to end the continuing attack on Iraq, to protect Iraqi citizens and to enable Iraqi forces to regain control of the borders of Iraq by striking ISIL sites and military strongholds in Syria, as necessary and proportionate measures.”) (emphasis added); United Kingdom, S/2015/688 (Sept. 8, 2015) (“On 21 August 2015, armed forces of the United Kingdom of Great Britain and Northern Ireland carried out a precision air strike against an ISIL vehicle in which a target known to be actively engaged in planning and directing imminent armed attacks against the United Kingdom was travelling. This air strike was a necessary and proportionate exercise of the individual right of self-defence of the United Kingdom.”) (emphasis added); United Kingdom, S/2015/928 (Dec. 3, 2015) (“In accordance with Article 51 of the Charter of the United Nations, and further to our letters of 25 November 2014 (S/2014/851) and 7 September 2015 (S/2015/688), I am therefore writing to report to the Security Council that the United Kingdom of Great Britain and Northern Ireland is taking necessary and proportionate measures against ISIL/Daesh in Syria, as called for by the Council in resolution 2249 (2015), in exercise of the inherent right of individual and collective self-defence.”) (emphasis added).
[279]. See United States, S/1998/780 (Aug. 20, 1998), at 1 (“In response to these terrorist attacks, and to prevent and deter their continuation, United States armed forces today struck at a series of camps and installations used by the Bin Ladin organization to support terrorist actions against the United States and other countries. In particular, United States forces struck a facility being used to produce chemical weapons in the Sudan and terrorist training and basing camps in Afghanistan. [¶] These attacks were carried out only after repeated efforts to convince the Government of the Sudan and the Taliban regime in Afghanistan to shut these terrorist activities down and to cease their cooperation with the Bin Ladin organization. That organization has issued a series of blatant warnings that ‘strikes will continue from everywhere’ against American targets, and we have convincing evidence that further such attacks were in preparation from these same terrorist facilities. The United States, therefore, had no choice but to use armed force to prevent these attacks from continuing. [¶] In doing so, the United States has acted pursuant to the right of self-defence confirmed by Article 51 of the Charter of the United Nations. The targets struck, and the timing and method of attack used, were carefully designed to minimize risks of collateral damage to civilians and to comply with international law, including the rules of necessity and proportionality. [¶] It is the sincere hope of the United States Government that these limited actions will deter and prevent the repetition of unlawful terrorist attacks on the United States and other countries.”); United States, S/2014/695 (Sept. 23, 2014) (“States must be able to defend themselves, in accordance with the inherent right of individual and collective self-defence, as reflected in Article 51 of the Charter of the United Nations, when, as is the case here, the government of the State where the threat is located is unwilling or unable to prevent the use of its territory for such attacks. The Syrian regime has shown that it cannot and will not confront these safe havens effectively itself. Accordingly, the United States has initiated necessary and proportionate military actions in Syria in order to eliminate the ongoing ISIL threat to Iraq, including by protecting Iraqi citizens from further attacks and by enabling Iraqi forces to regain control of Iraq’s borders. In addition, the United States has initiated military actions in Syria against al-Qaida elements in Syria known as the Khorasan Group to address terrorist threats that they pose to the United States and our partners and allies.”) (emphasis added).
[280]. See Canada, S/2015/221 (Mar. 31, 2015) (“Canada’s military actions against ISIL in Syria are aimed at further degrading ISIL’s ability to carry out attacks.”) (emphasis added).
[281]. See Iran, S/1998/934 (Oct. 8, 1998) (“At 6.30 a.m., local time, the Taliban militia launched an attack, using mortar and Dush-K, against the territory of the Islamic Republic of Iran between the Ibrahim Khani and Kondeh Souz border posts in Khorassan Province. The Iranian armed forces took some limited and proportionate measures, in accordance with Article 51 of the Charter, to repel the Taliban attack. At 9.30 a.m., the cross-border attack by the Taliban militia, constituting a flagrant aggression and provocation, was repelled and military operation was halted.”) (emphasis added); Iran, S/2001/381 (Apr. 19, 2001), at 1 (“[I]n response to numerous operations by the MKO terrorist organization from its bases inside the territory of Iraq against the Islamic Republic of Iran resulting in human and material losses over the last several months, the armed forces of the Islamic Republic of Iran, in accordance with Article 51 of the Charter of the United Nations, took a limited and proportionate defensive measure against a number of the MKO command and control, training and logistic bases inside Iraq. This operation, which began at 4.15 and concluded at 7.30 in the early hours of this morning, targeted the following MKO bases: … The Government of the Islamic Republic of Iran emphasizes that this limited and proportionate operation was carried out to stop cross-border attacks against the Islamic Republic of Iran from Iraqi territory by the MKO terrorist organization harboured in Iraq, and should not be construed as infringing the territorial integrity of Iraq.”) (emphasis added).
[282]. See Israel, S/2005/609 (Sept. 28, 2005), at 1 (“... Hamas showered more than 40 Kassam artillery rockets onto the Israeli town of Sderot and elsewhere in the Negev, wounding five persons, two moderately, causing extensive damage and forcing inhabitants of the region to seek bomb shelters and reinforced rooms. [¶] In response to the Kassam attacks and as an act of self-defence, Israel deployed forces around the Gaza Strip to prevent further assaults, targeted the terrorist infrastructure of Gaza and pursued a campaign to arrest wanted Palestinian terrorists.”) (emphasis added).
[283]. See Turkey, S/2018/53 (Jan. 22, 2018), at 1 (“In order to counter this terrorist threat, Turkey initiated a military operation on 20 January 2018 against these terrorist elements. The operation is aimed at ensuring our border security, neutralizing terrorists in Afrin and saving the brotherly Syrians. Accordingly, the operation will target only terrorists and their hideouts, shelters, emplacements, weapons, vehicles and equipment.”) (emphasis added).
[284]. See United Kingdom, S/2001/947 (Oct. 7, 2001) (“These forces have now been employed in exercise of the inherent right of individual and collective self-defence, recognized in Article 51, following the terrorist outrage of 11 September, to avert the continuing threat of attacks from the same source.”) (emphasis added).
[285] See United States, S/2001/946 (Oct. 7, 2001), at 1 (“In response to these attacks, and in accordance with the inherent right of individual and collective self-defence, United States armed forces have initiated actions designed to prevent and deter further attacks on the United States. These actions include measures against Al-Qaeda terrorist training camps and military installations of the Taliban regime in Afghanistan.”) (emphasis added); United States, S/2014/417 (June 18, 2014) (reporting that the United States “has taken action in Libya to capture Ahmed Abu Khattalah, a senior leader of the Libyan militant group Ansar al-Sharia-Benghazi in Libya. .... [¶] ... [T]he United States Temporary Mission Facility and Annex in Benghazi, Libya, were attacked in September 2012, and the United States Ambassador to Libya and three other Americans were killed. Following a painstaking investigation, the United States Government ascertained that Ahmed Abu Khattalah was a key figure in those armed attacks. The investigation also determined that he continued to plan further armed attacks against United States persons. [¶] The measures we have taken to capture Abu Khattalah in Libya were therefore necessary to prevent such armed attacks, and were taken in accordance with the United States’ inherent right of self-defence.”) (emphasis added).
[286]. See Israel, S/2004/465 (June 8, 2004), at 2.
[287]. U.N. Security Council, resolution 1553 (2004), S/RES/1553(2004), July 29, 2004, OPs 3–4.
[288]. See United States, S/2014/695 (Sept. 23, 2014).
[289]. See United Kingdom, S/2014/851 (Nov. 26, 2014); United Kingdom, S/2015/688 (Sept. 8, 2015).
[290]. See Turkey, S/2015/127 (Feb. 23, 2015); Turkey, S/2015/563 (July 24, 2015).
[291]. See Canada, S/2015/221 (Mar. 31, 2015).
[292]. See France, S/2015/745 (Sept. 9, 2015).
[293]. See Australia, S/2015/693 (Sept. 9, 2015).
[294]. See Dapo Akande & Marko Milanovic, The Constructive Ambiguity of the Security Council’s ISIS Resolution, EJIL: Talk!, Nov. 21, 2015, https://www.ejiltalk.org/the-constructive-ambiguity-of-the-security-councils-isis-resolution/, https://perma.cc/V5BE-W8Q7.
[295]. For example, compare Cardiel et al., above note 244, at 16–17 (stating that “[e]xamples of the use of force to respond to attacks by non-State actors which have met with general acquiescence include … the international coalition’s intervention in Syria against ISIL beginning in 2014.”) (emphasis added; citations omitted) with Remarks by Patrick Luna, above note 210, at 54–55.
[296]. See United Kingdom, S/2015/928 (Dec. 3, 2015).
[297]. See Germany, S/2015/946 (Dec. 10, 2015).
[298]. See Denmark, S/2016/34 (Jan. 13, 2016).
[299]. See the Netherlands, S/2016/132 (Feb. 10, 2016).
[300]. See Norway, S/2016/513 (June 3, 2016).
[301]. See Belgium, S/2016/523 (June 9, 2016).
[302]. See Claus Kreß & Benjamin K. Nußberger, The Entebbe Raid—1976, in The Use of Force in International Law: A Case-based Approach 231 (Tom Ruys & Olivier Corten eds., Alexandra Hofer assistant ed., 2018).
[303]. See id.
[304]. Id. at 232 (emphasis added; citations omitted).
[305]. Mary Ellen O’Connell, American Exceptionalism and the International Law of Self-Defense, 31 Denv. J. Int’L L. & Pol’y. 43, 51 (2002).
[306]. Id.
[307]. See Cardiel et al., above note 244, at 10 n.34 (citing to Francis Kofi Abiew, The Evolution of the Doctrine and Practice of Humanitarian Intervention 123 (1999)).
[308]. See also Hakimi, above note 248, at 14; Scharf, above note 247, at 50.
[309]. See Cardiel et al., above note 244, at 5 n.19 (“Examples of the use of low-level force to respond to attacks by non-State actors which have met with acquiescence include Russia’s use of force against Chechen rebels in Georgia in 2002, Turkey’s use of force against the Kurds from 1999, and U.S. airstrikes against Al Qaeda targets in Afghanistan in 1998 in retaliation for the bombings of U.S. embassies in Kenya and Tanzania.”) (emphasis added; citing to Elena Chachko & Ashley Deeks, Which States Support the ‘Unwilling and Unable’ Test?, Lawfare, Oct. 10, 2016, https://www.lawfareblog.com/whoboard-unwilling-or-unable, permalink: https://perma.cc/469Z-TJLL).
[310]. Cardiel et al., above note 244, at 16–17 (“Examples of the use of force to respond to attacks by non-State actors which have met with general acquiescence include Russia’s use of force against Chechen rebels in Georgia in 2002, Turkey’s use of force against the Kurds from 1999, the United States’ intervention in Afghanistan after the 9/11 attacks, and the international coalition’s intervention in Syria against ISIL beginning in 2014.”) (emphasis added; citations omitted).
[311]. See, e.g., Byers, above note 245, at 634 (“In these ways, the United States extended its claim of self-defence to justify action against terrorists who had already committed acts of violence amounting to an armed attack, and against a state that was willingly harbouring them. Although the lower threshold (harbouring rather than controlling) was a step beyond the law as it existed prior to 11 September 2001, it was a much smaller step than if the United States had claimed a right to attack terrorists who simply happened to be within another country’s territory. For these reasons, the claim to be acting in self-defence against both Al Qaeda and the Taliban—and the modification to customary international law entailed by that claim—had a much better chance of securing the expressed or tacit support of other countries. [¶] Secure support it did: through the Security Council resolutions discussed above, it secured the statements of more than 100 countries, and acquiescence on the part of all but two others. As a result of this nearly unanimous state practice, the US intervention in Afghanistan in 2001 was legal under the customary international law of self-defence, as it developed in the immediate aftermath of the 11 September 2001 attacks.”) (emphasis added); see also Cardiel et al., above note 244, at 16–17 (“Examples of the use of force to respond to attacks by non-State actors which have met with general acquiescence include … the United States’ intervention in Afghanistan after the 9/11 attacks….”) (emphasis added; citation omitted).
[312]. Kirgis, above note 245. See also J. Patrick Kelly, The International Law of Force and the Fight against Terrorism, 21 Del. Law. 18, 19 (2003) (“One could persuasively argue that the United Nations acquiescence and the reaction of other nations have expanded the concept of self-defense to include the use of force against States harboring terrorists.”).
[313]. Theresa Reinold, State Weakness, Irregular Warfare, and the Right to Self-defense Post-9/11, 105 Am. J. Int’l L. 244, 252 (2011). See also José E. Alvarez, Hegemonic International Law Revisited, 97 Am. J. Int’l L. 873, 879 (2003) (“Given the legislative efforts in at least one of those resolutions (1373) and the tendency for many of the Council's actions to be read as having broader normative effect, the prospective endorsement of individual and collective self-defense by the Council, together with its later acquiescence in Operation Enduring Freedom, may signal, depending on how the Council's license comes to be interpreted by its licensee, the advent of three new general rules with respect to defensive force in the age of terrorism: [¶] (1) Terrorist violence, at least when of the scale of the events of September 11, 2001, and even when undertaken by a nonstate actor, may constitute an ‘armed attack’ for purposes of UN Charter Article 51. [¶] (2) A state’s assistance to, harboring of, or post hoc ratification of violent acts undertaken by individuals within its territory, or perhaps even mere negligence in controlling such individuals, may make that state responsible for those acts and justify military action against it. In other words, such state action (or inaction) may constitute a breach of the state’s own duty not to violate UN Charter Article 2(4). [¶] (3) The right to respond with military force against both terrorist individuals and harboring states does not become impermissible retaliation or illegal anticipatory self-defense, or exceed the rules of proportionality, merely because the threat of continued terrorist attack remains clandestine and unpredictable (as it has been since 9/11).”) (emphasis added).
[314]. Hakimi, above note 248, at 14.
[315]. Id.
[316]. Monica Hakimi & Jacob Katz Cogan, The Two Codes on the Use of Force, 27 Eur. J. Int’l L. 257, 263 (2016) (emphasis added).
[317]. Ruys, above note 250, at 355; see id. at 344 (“In sum, the EU essentially urged Turkey to seek a political solution and to avoid disproportionate military action. European countries did not regard military action as the best answer to PKK violence, but carefully refrained from formally condemning Turkey’s behaviour.”) (emphasis added); id. (“Other reactions from the international community [that is, other than that of the U.S. and Iraq] were generally analogous to the EU approach.”) (emphasis added); and id. at 355: (“Against this background, the Turkish intervention [in Iraq] of 2007–08, combined with the condoning attitude of the international community, adds to the evidence in state practice of an evolution towards a more flexible … interpretation of self-defence in response to attacks by non-state actors which a state has been unwilling or unable to prevent.”) (emphasis added). See also Scharf, above note 247, at 50.
[318]. Scharf, above note 247, at 24–25 (“Professor Myers McDougle [sic] of Yale Law School famously described the customary international law formation process as one of continuous claim and response. To illustrate this process, consider the question of whether international law permits a State to use force to arrest a terrorist leader in another State without the latter’s consent—a question that recently arose when the United States kidnapped an al-Qaeda leader from Libya in October 2013. The claim may be express, such as demanding that its special forces be allowed to enter the territorial State to arrest the terrorist, or implicit, such as sending its special forces into the territorial State without its permission to apprehend the terrorist. The response to the claim may in turn be favorable, such as consenting to the operation or refraining from protesting the extraterritorial apprehension. In such case, the claim and response will begin the process of generating a new rule of customary international law. Some States may imitate the practice and others may passively acquiesce to it.”) (emphasis added; citations omitted).
[319]. Id. at 50–51 (citations omitted).
[320]. Id. at 50.
[321]. Id. at 50 n.192 (citations omitted).
[322]. O.A.S., OEA/Ser.G, CP/RES. 930 (1632/08), Mar. 5, 2008, https://www.oas.org/council/sp/resoluciones/res930.asp, permalink: https://perma.cc/9AP3-J57D (“Que el hecho ocurrido constituye una violación de la soberanía y de la integridad territorial del Ecuador y de principios del derecho internacional”).
[323]. See Schweiger, Listen, above note 1; Starski, above note 6; Elisabeth Schweiger, The risks of remaining silent: international law formation and the EU silence on drone killings, 1 Global Affairs 269 (2015). See also André de Hoogh, Restrictivist Reasoning on the Ratione Personae Dimension of Armed Attacks in the Post 9/11 World, 29 Leiden J. Int’l L. 19, 39 (2016) (discussing the use of silence in legal argumentation in this field).
[324]. Christine Gray, The Limits of Force, 376 Recueil des Cours 101, 102–3 (2016).
[325]. Id. at 103.
[326]. Carsten Stahn, Collective Security and Self-Defense after the September 11 Attacks, 10 Tilburg For. L. Rev. 10, 41 (2002).
[327]. See Byers, above note 311 and the accompanying text.
[328]. See id. at 637–38 (“Another set of questions arises with regard to the US reliance on a claim of self-defence despite the availability of better alternative arguments, such as Resolution 1373 providing Chapter VII authorization, or the ‘status of forces agreement’ with Afghanistan signalling consent. Does state practice consistent with a legally uncertain self-defence claim matter, if the operation itself is legal for other, more certain reasons? More specifically, did countries refrain from opposing the [U.S.] self-defence claim because they knew that a better justification was available—even if the United States did not make use of it? In such circumstances, acquiescence should not be considered state practice in favour of a claim because, once again, exceptions to the prohibition on force must be narrowly construed. [¶] If states respond directly and positively to a self-defence claim, that practice does matter. As we saw above, there was widespread and explicit support in late 2001 for the US claim to a right of self-defence against terrorists who had already committed an act of violence amounting to an armed attack, and a country which was harbouring but not controlling them. [¶] Later, however, the United States sought to extend its self-defence claim to support a long-term presence in Afghanistan, after Al Qaeda had been pushed out of the country, in order to prevent the return to power of a group that had harboured it. This time, there was no such widespread and explicit support for the claim. Instead there was acquiescence, which could just as easily have been based on knowledge of the Afghan Government’s consent. Given that the United States was seeking to stretch the right of self-defence further, thus broadening an exception to the prohibition on the use of force (which protects state sovereignty), silence in the face of the continuation of Operation Enduring Freedom should not be interpreted as support for the claim.”) (emphasis added; citation omitted).
[329]. See O’Connell, above note 305, at 51.
[330]. Id.
[331]. Id.
[332]. Jules Lobel & Michael Ratner, Bypassing the Security Council: Ambiguous Authorizations to Use Force, Cease-Fires and the Iraqi Inspection Regime, 93 Am. J. Int’l L. 124, 130 (1999).
[333]. Id.
[334]. Elinor Buys & Andrew Garwood-Gowers, The (Ir)Relevance of Human Suffering: Humanitarian Intervention and Saudi Arabia’s Operation Decisive Storm in Yemen, J. Conflict & Sec. L. 1 (2018) (citation omitted).
[335]. Id. (citations omitted).
[336]. Id. at 25 (citations omitted). Nußberger argues that “a policy of silence characterised the … debate in the Security Council [that ensued after adopting of resolution 2216 in 2015], as states hardly addressed the issue of legality.” Benjamin Nußberger, Military strikes in Yemen in 2015: intervention by invitation and self-defence in the course of Yemen’s ‘model transitional process,’ 4 J. Use of Force & Int’l L. 110, 124 (2017) (emphasis added).
[337]. Buys & Garwood-Gowers, above note 334, at 25 (citation omitted).
[338]. Jake Rylatt, The Use of Force against ISIL in Libya and the Sounds of Silence, EJIL:Talk!, Jan. 6, 2016, https://www.ejiltalk.org/the-use-of-force-against-isil-in-libya-and-the-sounds-of-silence/, permalink: https://perma.cc/N2QQ-E2VT.
